DESCRIPTION: The focus of the work in this investigator's laboratory is to determine the mechanisms of activation by a variety of locally active chemicals of somatic and visceral afferent fibers involved in reflex cardiovascular regulation during muscle contraction and visceral ischemia. The first aim investigates serotonin and histamine involvement in the interstitial lymph during visceral ischemia. The second aim looks at the muscle mechanosensitive nerve fibers in mesenteric ischemia. The third aim addresses the hypothesis that increased bradykinin release resulting from excess lactic acid leads to the formation of prostaglandins and leukotrienes. The overall result accounts for the reflex cardiovascular changes observed during visceral ischemia. Finally, the role of reactive oxygen species on the reflex and the differences in chemical and mechanical stimuli during sinusoidal versus static muscle contraction will be investigated.